After an incident in which a gun fired by Sebumi Takeru mysteriously turned around and hit one of his subordinate, Sebumi, the elite SIT unit's platoon leader was pushed to work in the most unpopular department, a special department named Mishou (Unidentified Crimes Unit), which crack cases without evidence, witnesses, or involving special organizations. Sebumi Takeru met his workmate, Toma Saya, a woman with an IQ of 201 and an arm wearing cast, who acted in a mysterious way that Sebumi could not even understand. When solving mysterious case together, the two encounter the superpower of unknown criminals, "SPEC". When deducing the different "SPEC" of different criminals, they fight with Ninomae Juichi, the powerful SPEC holder, and discover a mysterious world with SPECs, schemes, secrets and dangers.